Elements of Soil Science - Past Questions - 2061 Poush

Elements of Soil Science - Past / old Questions - 2061 Poush, Bachelor in Agricultural Engineering, Tribhuvan University, Nepal, Third semester,

 

Elements of Soil Science - Past Questions - 2061 Poush

TRIBHUVAN UNIVERSITY
INSTITUTE OF ENGINEERING
Examination Control Division
2061 Poush

Exam: Back
Level: B.E.
Programme: B. Agri.
Year / Part: II / I
Subject: Elements of Soil Science
Full Marks: 80
Pass Marks: 32
Time: 3 hrs.

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✓ Candidates are required to give their answers in their own words as far as practicable.
✓ Attempt any Five questions.
✓ All questions carry equal marks.
✓ Assume suitable data if necessary.

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1.
a) What are the general properties of soil colloids? Explain different types of soil colloids.
b) What are the advantages and limitations of soil tests as a guide to determine the kinds and rates of fertilizers to be used?

2.
a) Describe different forms of lime. Explain the role and action of lime in reducing soil acidity.
b) Nitrogen in the soil is fixed from the atmosphere, and it is also fixed by vermiculite clays and humus. Differentiate between these two processes of nitrogen fixation and explain the role played by microbes in each of the two processes.

3.
a) How are the edaphological views different from pedological views in the study of soils? Explain the process of soil formation.
b) Why are well-aggregated soils considered good for plant growth? Explain the process of aggregation in soils.

4.
a) What is soil moisture tension? Explain the purpose of preparing a soil moisture characteristic curve.
b) Differentiate between soil texture and soil structure. What behaviors of soils are controlled by soil texture?

5.
a) Explain the significance of soil temperature. What factors control the variation of soil temperature in the soil profile?
b) What are the causes of poor soil aeration? What are the consequences of poor soil aeration in crop production?

6.
Write short notes on any four of the following:
a) Phosphorus cycle
b) Anion exchange capacity
c) Soil pH
d) Dispersion and flocculation
e) Plough pan and traffic pan